ALTERNATIVE REDUCTIONS FOR DYNAMIC DEONTIC LOGICS

Abstract

One more recent approach to deontic logic – the logic of permission, obligation and prohibition – places deontic logic into a dynamic framework. In dynamic logics we differentiate between actions and assertions. For every action term an execution operator '[α] …' is introduced, which is read as 'every execution of leads to a state in which … holds'. Enriching our language by a violation constant V allows us to reduce deontic predicates in two obvious ways: (i) An action is forbidden iff every execution leads to a violation (ii) an action is forbidden iff at least one execution leads to a violation. Both reductions lead – besides being somewhat coarse grained – to implausible theorems. In our talk we will address the question where and how one may find more sophisticated reductions.